If you’re trying to clean up a house that has been flooded, be aware that you’re in a race against mold and bacteria, which can grow quickly in damp environments. Mold and mildew will develop quickly. According to FEMA, in just 24-48 hours of water exposure surfaces and materials can become contaminated with mold.
Mold is a major health risk that shouldn’t be taken lightly. Mold exposure can lead to several health-related problems. With its natural ability to travel through the air, the inhalation of mold spores can create a variety of respiratory ailments. Mold is especially dangerous for people with breathing problems caused by allergies or asthma.
Common side effects include asthma, allergies, respiratory infections, sinus infections and skin rashes. Mold in air ducts can cause allergic reactions. In some cases, mold exposure can even be fatal.
- FEMA Publication: Dealing with Mold and Mildew in your Flood Damages Home (PDF)
Mold isn’t the only threat from flooding. Bacteria may also be a problem if your house was soaked by sewage. Bacteria can cause dangerous gastrointestinal and skin infections.
That’s why it’s important to stop these pathogens before they take hold of your home.
Mold Professional Recommended
Both the CDC and the EPA recommend bringing in a trained professional to clean up mold that covers more than 100 square feet or a 10-foot-by-10-foot area. Some states require contractors that clean up mold to be licensed. At the minimum, anyone you hire should have experience getting rid of mold, references you can call, and liability insurance.

- The Mold Inspector Certification – NAMP Certified Mold Inspector Course – will instruct you to inspect for and control mold infestation and how to interpret the results of laboratory testing.
- The NAMP Certification is America’s oldest and most respected certification course and provide education and authoritative credentials for Mold Professionals.
- 6hrs: $495
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Professional mold removal contractors are individuals that are licensed and professionally trained in proper mold identification and removal techniques. These mold removal contractors use industrial equipment and cleaning supplies to kill and remove mold and mold colonies from the home.
During a mold inspection, a technician will perform a visual inspection and then test the air with a device referred to as a “sniffer.” Depending on the findings, the technician may send a mold sample in for lab testing.
FEMA Video: Eradicating Mold and Mildew
Hazards of Mold Infestation
Health officials say problems from exposure can follow if mold is disturbed through cleanup procedures. Also, mold is easily transferred from one surface to another. Infants, children, immune-compromised patients, pregnant women, individuals with existing respiratory conditions (allergies, multiple chemical sensitivity, and asthma) and the elderly appear to be at higher risks for adverse health effects from mold.
Symptoms include nose and throat irritation, wheezing, coughing, asthma attacks in individuals who have asthma, and lower respiratory tract infections (in children).
People with pre-existing respiratory conditions also may be susceptible to more serious lung infections. Thus, it is important to identify mold early and take steps to clean it up and prevent more mold activity.
Video: U.S. Dept. of Health and Human Services (HHS): Mold
Video: U.S. Dept. of Housing and Urban Development (HUD) – Mold
Additional Mold Safety and Cleanup Resources
- EPA – Mold prevention and cleanup
- Indoor Air Quality Home Page
- Flood Cleanup
- Emergency Preparedness for Indoor Environments
- Fact Sheet on Avoiding Indoor Air Quality Problems During Flood Cleanup (PDF)
- Homeowner’s and Renter’s Guide to Mold Cleanup After Disasters [PDF – 2.99 MB]
Advice on how to clean up mold in your home safely
CDC
- Mold Prevention Strategies and Possible Health Effects in the Aftermath of Hurricanes and Major Floods
A report by the CDC Mold Work Group addressing public health concerns related to limiting exposure to mold and identifying, preventing, and managing mold-related health effects following any natural disasters or other occurrences that results in flooding or major water intrusion. - NIOSH Recommendations for the Cleaning and Remediation of Flood-Contaminated HVAC Systems: A Guide for Building Owners and Managers
A guide for building owners or managers if heating, ventilating, and air conditioning systems are flooded … more - Population-Specific Recommendations for Protection From Exposure to Mold in Buildings Flooded After Hurricanes Katrina and Rita[PDF – 156 KB]
- Workplace Safety and Health
Dampness and mold remediation advice from NIOSH for workers…more
EPA
- A Brief Guide to Mold, Moisture and Your Home
EPA provides advice on mold cleanup, control, and prevention …more - Fact Sheet: Flood Cleanup – Avoiding Indoor Air Quality Problems
Flooding in a home or building can affect long-term indoor air quality — advice for cleanup, repairs, and personal safety …more - Mold Remediation in Schools and Commercial Buildings
Key steps in investigating, evaluating, and remediating moisture and mold problems in schools …more - Preventing condensation in your home
If it’s hot & humid outside, too much air conditioning can lead to condensation on surfaces and this excess moisture can lead to mold growth [see page 12]. - Replacing your flooring after a flood
If you are repairing your home or building after a flood or hurricane, to prevent mold growth you should be sure your foundation is dry before you replace the flooring.